1. Field of the Invention
The present invention concerns a return device for an operating member of a lock adapted to be embedded within the thickness of an opening panel.
It also concerns a casing of a lock, espagnolette-lock or the like of the above kind for doors, windows, french doors or the like.
2. Description of the Prior Art
In the prior art there are many examples of espagnolette-locks of the above type which are generally adapted to operate simultaneously a catch bolt, a lock bolt and at least one locking rod or one actuator rod of locking accessories such as rollers cooperating with a keeper in the fixed frame.
In a espagnolette-lock of the above kind, as described in French patent application 2 747 422 in the name of the Applicant, a nut is attached to an operating member such as a door handle which engages at least with an operating square pin at the center of the nut.
Rotating the nut one way operates the catch bolt against a return spring which holds the catch bolt projecting from the lock front plate.
The nut also cooperates with a bracket to the ends of which the espagnolette bolts are fixed so that the espagnolette rods are deployed or retracted according to the direction in which the nut turns.
After each rotation of the operating member it and the nut that rotates with it must be returned to their original position.
To this end, the aforementioned patent application describes a spring cooperating with a member which is mobile inside the lock casing and is adapted to move in a longitudinal direction when the nut turns on its axis. Pinion means centered on the nut axis are adapted to mesh with the teeth of a rack attached to the mobile member.
The spring lies inside a housing formed in the casing and the mobile member has two projecting parts adapted to engage with respective ends of the spring.
The spring housing supports the rack of the mobile member and includes a plate adapted to engage in a corresponding opening at the rear of the lock casing.
However, an operating member return device of the above kind has a large number of parts (housing, spring, mobile member carrying the rack) and requires a large number of assembly operations to fix the assembly into the casing of the espagnolette-lock.
French patent 84 13 687 in the name of Establishments DREVET et CIE discloses a lock for doors or the like comprising a casing enclosing a nut for operating the catch bolt returned to a rest position by a spring member. A sliding member carrying a rack adapted to mesh with the teeth of a pinion attached to the nut includes a housing containing the spring member. The latter member is between the back of the housing and a transverse shaft fastened to the casing which is adapted to compress the spring member when the sliding member moves longitudinally in response to rotation of the nut.
However, a nut return device of the above kind is not suitable as a return spring for a nut which can turn about its axis in both directions.
Furthermore, the spring member cannot escape from the housing in the sliding member when the latter is fixed to the casing, as the transverse shaft of the casing then cooperates with the open end of the sliding member through which the spring member is inserted.
An object of the present invention is to overcome the aforementioned drawbacks and to propose a return device for an operating member that is simpler to manufacture and to fit.